The present invention relates to the use of copolymers with a stiff hydrophilic skeleton which are obtained by radical polymerization or by polycondensation and which are grafted by flexible hydrophobic macromonomers in and for the preparation of cosmetic or dermatological compositions, and to the compositions employed.
For numerous cosmetic applications, in particular those intended for the treatment and care of the hair, skin or eyelashes, use is made of polymers capable, after application to the substrate to be treated and drying, of forming a deposit having mechanical properties and adhesive properties. From this viewpoint, the aim is to find polymers with a hydrophilic nature, in order to be easily removed under the action of an aqueous solution of surfactants. At the same time, the aim is to obtain a hydrophobic surface deposit in order, on one hand, to withstand the surrounding moisture, in particular a deposit which is non-hygroscopic to the touch, a deposit which withstands rain (hair applications or skin applications) or a deposit which withstands lachrymal fluid (mascaras). On the other hand, the aim is to find a hydrophobic deposit in order to introduce cosmetic properties, such as softness to the touch, generally conferred by hydrophobic substances in cosmetics.
In order to combine all these characteristics, polymers of different hydrophilicity and of different hydrophobicity are generally mixed or else a hydrophilic polymer is used in combination with a hydrophobic substance. It is generally difficult to completely control the stratification of these mixtures after drying the deposit in order to obtain both good mechanical and adhesive properties and a hydrophobic surface.
Another problem relating to the deposited polymers arises in the hair field, in particular in the context of products for form retention of or for setting the hair. This is because it is often difficult to adjust the properties of the polymer which has to be deposited in order to simultaneously obtain good setting of the hair, good hold of this setting and easy removal on combing or brushing. This is because, in order to achieve good setting of the hair, the setting polymer is plasticized in order to bring its phase transition temperature to room temperature. Under these conditions, removal on brushing or combing is then difficult.
One of the objectives of the present invention is thus to use, in cosmetic or dermatological compositions, polymers having satisfactory film-forming properties which give a hydrophobic surface and which can be easily removed under the action of an aqueous solution of surfactants.
Another objective of the invention is to use, in and for the preparation of hair styling compositions, polymers having both significant characteristics of setting which are highly resistant to slight mechanical stresses and good stiffness, without it being necessary to add a plasticizer or at least with small amounts of plasticizer, in order subsequently to be removed very easily on brushing or combing.
The inventors have discovered, surprisingly, that these objectives could be achieved by using, in and for the preparation of cosmetic or dermatological compositions, specific grafted copolymers, the skeleton of which is hydrophilic and stiff and composed of a copolymer obtained by radical polymerization or by polycondensation, comprising, on the chain of the skeleton, at least one flexible hydrophobic macromonomer graft.
The subject-matter of the present invention is the use, in and for the preparation of cosmetic or dermatological compositions, of a grafted copolymer, the skeleton (S) of which is composed of a hydrophilic copolymer, with a glass transition temperature Tg greater than 25xc2x0 C., obtained by radical polymerization or by polycondensation, comprising, on the chain of the skeleton (S), at least one graft composed of a hydrophobic macromonomer (M) with a glass transition temperature T""g of less than 25xc2x0 C.
The present invention also relates to cosmetic or dermatological compositions containing, in a cosmetically acceptable medium, at least one grafted copolymer, the skeleton (S) of which is composed of a hydrophilic copolymer, with a glass transition temperature Tg greater than 25xc2x0 C., obtained by radical polymerization or by polycondensation, comprising, on the chain of the skeleton, at least one graft composed of a hydrophobic macromonomer (M) with a glass transition temperature T""g of less than 25xc2x0 C.
Other subject-matters will become apparent in the light of the description and examples which follow.
xe2x80x9cHydrophilic copolymerxe2x80x9d is understood to mean, throughout the text of the description, any copolymer which is soluble or dispersable in water, lower (C1-4) alcohols or mixtures of water and of lower alcohol(s).
xe2x80x9cHydrophobic polymerxe2x80x9d is understood to mean, throughout the text of the description, any polymer which is insoluble in water, lower (C1-C4) alcohols or mixtures of water and of lower alcohol(s).
xe2x80x9cMacromonomerxe2x80x9d is understood to mean, throughout the text of the description, any oligomer comprising, on just one end, either a group possessing ethylenic unsaturation capable of polymerizing by the radical route with the monomers constituting the skeleton (S) of the copolymer of the invention and of grafting onto the polymeric chain of the skeleton (S); or a reactive functional group capable of reacting with the monomers (A) and (B) of the skeleton (S) or else with the preformed skeleton (S).
The macromonomers (M) grafted by covalent bonding to the polymeric chain of the skeleton (S) of the copolymers of the invention are preferably chosen from hydrocarbon-comprising, hydrofluorocarbon comprising or fluorocarbon-comprising macromonomers having a glass transition temperature T""g of less than 25xc2x0 C.
The macromonomers (M) have a glass transition temperature T""g preferably of less than or equal to 10xc2x0 C. and more particularly of less than or equal to 0xc2x0 C.
Furthermore, the macromonomers (M) are hydrophobic, that is to say insoluble in water, and have a surface tension generally of less than or equal to 40 dyne/cm at 20xc2x0 C.
They preferably exhibit an average molecular weight, measured at the peak tip by steric exclusion chromatography, ranging from 200 to 20,000.
Mention may be made, among the macromonomers (M) grafted onto the copolymers of the invention, of:
(a) polymers and copolymers of linear or branched C2-C18 alkyl acrylate or methacrylate with a T""g of less than 25xc2x0 C. and exhibiting a terminal group chosen from vinyl, allyl, methallyl, (meth)acryloyl, ethacryloyl, vinylbenzoyl, vinylbenzyl, C1-C4 alkenyl or C1-C6 cycloalkenyl or a terminal reactive functional group capable of interacting with the skeleton (S) or the monomers constituting it (such as xe2x80x94OH, xe2x80x94NH2, xe2x80x94COOH or S anhydride) or a terminal reactive functional group capable of participating in a polycondensation (such as diol, diamine or dicarboxylic acid), among which may in particular be mentioned: poly(butyl acrylate) macromonomers with a monomethacrylate end, such as the products sold under the name [lacuna] by the company Toa Gosei; poly(butyl acrylate) macromonomers with a monomethacrylate end; poly(2-ethylhexyl acrylate) macromonomers with a monoacrylate or monomethacrylate end; poly(dodecyl acrylate) or poly(dodecyl methacrylate) macromonomers; or poly(stearyl acrylate) or poly(stearyl methacrylate) macromonomers;
(b) polyolefins with a T""g of less than 25xc2x0 C. and exhibiting a terminal group possessing ethylenic unsaturation or a terminal reactive functional group capable of interacting with the skeleton (S) or the monomers constituting it or a terminal reactive functional group capable of participating in a polycondensation, among which mention may in particular be made of:
polyethylene macromonomers; polypropylene macromonomers; polyethylene/polypropylene copolymer macromonomers; polyethylene/polybutylene copolymer macromonomers; polyisobutylene macromonomers; polybutadiene macromonomers; polyisoprene macromonomers; or polyolefin macromonomers possessing a very short chain, such as, for example, hydrogenated polybutadiene or hydrogenated polyisoprene macromonomers comprising only 3 or 4 repeat units and more particularly phytol (3,7,11,15-tetramethylhexadec-2-en-1-ol) acrylate or methacrylate.
(c) vinyl polymers with a T""g of less than 25xc2x0 C. and exhibiting a terminal group possessing ethylenic unsaturation or a terminal reactive functional group capable of interacting with the skeleton (S) or the monomers constituting it or a terminal reactive functional group capable of participating in a polycondensation;
(d) polymers or copolymers of fluorinated or perfluorinated monomers with a T""g of less than 25xc2x0 C. and exhibiting a terminal group possessing ethylenic unsaturation or a terminal reactive functional group capable of interacting with the skeleton (S) or the monomers constituting it or a terminal reactive functional group capable of participating in a polycondensation, among which mention may particularly be made of perfluoroalkyl (meth)acrylate homopolymers or copolymers;
(e) polyesters with a T""g of less than 25xc2x0 C. and exhibiting a terminal group possessing ethylenic unsaturation or a terminal reactive functional group capable of interacting with the skeleton (S) or the monomers constituting it or a terminal reactive functional group capable of participating in a polycondensation, among which mention may in particular be made of aliphatic polyesters composed of long carbonaceous sequences, such as polyesters of 12-hydroxystearic acid or polysebacates of aliphatic diols composed of long carbonaceous sequences (for example hexanediol).
The macromonomers (M) are present in the composition of the copolymers of the invention in a proportion preferably ranging from 1 to 60% by weight with respect to the total weight of the grafted copolymer.
The grafted copolymers in accordance with the present invention preferably exhibit an average molecular weight, measured at the peak tip by steric exclusion chromatography, ranging from 10,000 to 5,000,000.
They are generally hydrophilic, namely soluble or dispersable in aqueous media or alcoholic or aqueous/alcoholic media based on lower alcohols. They can be non-ionic, anionic, cationic or amphoteric, the ionic groups preferably being situated in the structure of the skeleton (S) in order to introduce hydrophilicity.
The skeleton (S) of the copolymers of the invention has a phase transition temperature Tg of greater than 25xc2x0 C. and preferably of greater than or equal to 35xc2x0 C.
The skeleton (S) of the copolymers of the invention is composed of a copolymer obtained by radical polymerization or by polycondensation.
The skeleton (S) obtained by the radical route preferably results from the polymerization:
(a) of at least one monomer or one mixture of monomers (A) possessing ethylenic unsaturation, and
(b) of at least one monomer or one mixture of monomers (B) which are polar and hydrophilic and which possess ethylenic unsaturation, the monomers (A) and (B) being chosen so that the phase transition temperature Tg of the skeleton (S) is greater than 25xc2x0 C.
The monomers of the type (A) are chosen, for example, from the group consisting of:
acrylic or methacrylic esters or amides obtained from linear, branched or cyclic aliphatic alcohols and/or from aromatic alcohols, preferably C1-4 alcohols, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate or tert-butylacrylamide;
vinyl, allyl or methallyl esters or amides obtained from linear, branched or cyclic aliphatic alcohols and/or from aromatic alcohols, preferably C1-C6 alcohols, such as vinyl acetate, vinyl propionate, vinyl benzoate or vinyl tert-butylbenzoate;
olefins, such as ethylene, propylene, styrene or substituted styrene;
fluorinated or perfluorinated acrylic or vinyl monomers;
their mixtures.
The monomers of the type (B) of the invention are chosen from anionic, cationic, amphoteric or non-ionic, hydrophilic and polar monomers possessing ethylenic unsaturation, or their mixtures.
Mention may be made, among the anionic monomers (B), of:
monomers comprising at least one acidic functional group, in the free form or else in the partially or completely neutralized form, such as monocarboxylic acids, such as acrylic, methacrylic or crotonic acid; dicarboxylic acids or acid anhydrides, as well as their monoesters or monoamides, such as maleic anhydride, in the diacid, monoester or monoamide form, or itaconic acid;
monomers comprising at least one sulphonic acid functional group, in the free form or else in the partially or completely neutralized form, such as vinyl- or styrenesulphonic acid or 2-acrylamido-2-methylpropanesulphonic acid;
monomers comprising at least one phosphoric or phosphonic acid functional group, in the free form or else in the partially or completely neutralized form.
The anionic monomers (B) are preferably partially or completely neutralized by a monobasic compound, such as an inorganic base, for example sodium hydroxide or potassium hydroxide, or an aminoalcohol, for example taken from the group consisting of 2-amino-2-methyl-1-propanol (AMP), triethanolamine, triisopropanolamine (TIPA), monoethanolamine, tri(2-hydroxypropyl)amine, 2-amino-2-methyl-1,3-propanediol (AMPD) or 2-amino-2-hydroxymethyl-1,3-propanediol.
Mention may be made, among the cationic monomers (B), of:
monomers comprising an amine functional group, in the free form or else partially or completely neutralized or else partially or completely quaternized, such as dimethylaminoethyl (meth)acrylate, dimethylaminoethyl-methacrylamide, vinylamine, vinylpyridine or diallyldimethylammonium chloride.
The cationic monomers (B) are preferably partially or completely neutralized by an inorganic or organic acid, such as hydrochloric, acetic, lactic or glycolic acid, or else partially or completely quaternized by an alkyl, cycloalkyl or aryl halide or a dialkyl sulphate (dimethyl or diethyl sulphate).
Mention may be made, among the amphoteric monomers (B), of carboxybetaines or sulphobetaines obtained by partial or complete quaternization of monomers possessing ethylenic unsaturation comprising an amine functional group by sodium salts of carboxylic acids possessing a mobile halide (sodium chloroacetate) or by cyclic sultones (propanesultone).
Mention may be made, among the non-ionic monomers (B), of:
C1-C4 hydroxyalkyl (meth)acrylates, such as 2-hydroxy-ethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate,
acrylamides, such as acrylamide, methacrylamide or di (C1-C4) alkyl (meth) acrylamides;
N-vinylpyrrolidone;
ethylene glycol (meth)acrylate, diethylene glycol (meth)acrylate or (meth)acrylates of polyethylene glycol possessing a hydroxyl or ether end.
The skeleton (S) obtained by polycondensation preferably results from the reaction:
(a) of at least one monomer or one mixture of monomers (Axe2x80x2) which is polycondensable and optionally
(b) of a monomer or a mixture of monomers (Bxe2x80x2), which is polycondensable with the monomer or monomers (Axe2x80x2), carrying at least one hydrophilic functional group contributing solubility or dispersabilty in water, alcoholic media or aqueous/alcoholic media, the monomers (Axe2x80x2) and (Bxe2x80x2) being chosen so that the phase transition temperature Tg of the skeleton (S) is greater than 25xc2x0 C.
The skeletons (S) of the polycondensate type are chosen, for example, from polyesters, polyamides, polyurethanes or polyesteramides.
The grafted copolymers in accordance with the invention can be obtained by direct radical copolymerization of monomers (A) and (B) as defined above constituting the skeleton (S) and of a macromonomer (M) exhibiting, on just one end, a group possessing ethylenic unsaturation which is copolymerizable with the monomers (A) and (B).
The direct radical polymerization can then be carried out in solution in a mutual solvent or a mixture of mutual solvents. It can also be carried out in heterogeneous medium, in particular in suspension or in emulsion in water, the macromonomer being dissolved in the mixture with the monomers (A) and (B) as defined above.
When the skeleton (S) is a polycondensate, such as a polyester, a polyamide, a polyurethane or a polyesteramide, the grafted copolymers in accordance with the invention can be obtained by direct polycondensation of monomers (Axe2x80x2) and (Bxe2x80x2) as defined above constituting the skeleton (S) and of a macromonomer (M) exhibiting, on just one end, two terminal reactive functional groups (for example, diol, diamine, dicarboxylic acid or acid anhydride) which are capable of polycondensating with the monomers (Axe2x80x2) and (Bxe2x80x2).
The direct polycondensation can be carried out in solution, in dispersion or in molten medium, according to a reaction of the esterification, amidation, transesterification or transamidation type.
Finally, the grafted copolymers in accordance with the invention can also be obtained by reacting the copolymer of the skeleton (S), synthesized beforehand, with a macromonomer (M) exhibiting an appropriate reactive terminal functional group, preferably a monofunctional one (amine, alcohol, carboxylic acid, anhydride, epoxy, and the like), capable of interacting with the skeleton (S). The reaction is generally carried out in solution or in a molten medium.
The cosmetic and dermatological compositions according to the invention thus comprise, in a cosmetically acceptable vehicle, the polymers as described above for applications as varied as those encountered, for example, in the hair or make-up field or alternatively the field of caring for the skin or any other cosmetic field in which the use of a film-forming substance is desirable or sought after.
The grafted copolymers according to the invention can be used alone as film-forming agent or else as additive in conventional film-forming agents in and for the preparation of cosmetic or dermatological compositions.
Mention may more particularly be made, among the applications preferably targeted by the present invention, of:
the field of hair products (washing, caring for or beautifying the hair), where the compositions according to the invention can be provided in the form of aerosols, of foams, of shampoos, of conditioners, of styling or treating lotions or gels, or of hair-shaping or hair-setting or alternatively fixing lacquers or lotions.
the field of make-up products, in particular for making up the nails, eyelashes or lips, where the compositions according to the invention can be provided in the form of nail varnishes, of mascaras or eyeliners, or of lipsticks.
in the field of skin care products (creams, milks, lotions, masks, serums or anti-sun products).
The concentration of grafted copolymer in the cosmetic or dermatological compositions of the invention is generally between 0.1 and 50% and preferably between 1 and 30% by total weight of the composition. It varies according to the cosmetic or dermatological application envisaged.
In the case of nail varnishes, this proportion is generally greater than or equal to 30% by weight when the copolymer of the invention is used alone as film-forming agent.
The cosmetically acceptable vehicle for the compositions according to the invention is preferably composed of water, of one or more cosmetically acceptable organic solvents or else of a mixture of water and of one or more cosmetically acceptable organic solvents.
Use is more particularly made, among these organic solvents, of lower C1-C4 alcohols, such as ethanol.
The grafted copolymers according to the invention are dissolved or in dispersion in the vehicle for the compositions of the invention.
The compositions can in addition and of course comprise various adjuvants intended to render it acceptable in a specific cosmetic application.
The compositions according to the invention can comprise conventional cosmetic additives chosen from fatty substances, such as mineral, vegetable, animal or synthetic oils, animal, fossil, vegetable, mineral or synthetic waxes, organic solvents, thickening agents, softeners, antifoaming agents, moisturizing agents, humectants, treating agents (agents for combating hair loss, antidandruff agents, and the like), antiperspirants, basifying agents, UV-A or UV-B or broad spectrum sunscreens, dyes, pigments, fragrances, plasticizers, preservatives, anionic, non-ionic or amphoteric organic polymers which are compatible with the grafted copolymers of the invention, and propellants, when the compositions are provided in the aerosol form.
Of course, a person skilled in the art will take care to choose the optional additional compound or compounds mentioned above so that the advantageous properties intrinsically attached to the compositions according to the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions.
Another subject-matter of the invention is a process for the cosmetic treatment of keratinous substances, such as the skin, hair, scalp, eyelashes, eyebrows, nails or lips, characterized in that it consists in applying, to the latter, a composition as defined above.